✨(frontend) the LanguagePicker now uses config as options

- config endpoint languages are used as available options for LanguagePicker
- updating the language from it, triggers an update on the user via API

src/frontend/apps/e2e/__tests__/app-impress/config.spec.ts

@@ -12,8 +12,8 @@ const config = {
   MEDIA_BASE_URL: 'http://localhost:8083',
   LANGUAGES: [
     ['en-us', 'English'],
-    ['fr-fr', 'French'],
-    ['de-de', 'German'],
+    ['fr-fr', 'Français'],
+    ['de-de', 'Deutsch'],
   ],
   LANGUAGE_CODE: 'en-us',
   POSTHOG_KEY: {},